Sunday, September 26, 2010

Living the PRESENT - the current decade!

The present decade (2001-2010) witnessed the metamorphosis of verification domain from adoloscence to maturity. A lot of the initiatives from the last decade paid off well to scale verification along with the ASIC designs while a lot of new investments were made keeping the next decade in mind. Some verification features that made their mark in this decade include -

1. System Verilog - touted as a one stop solution for HDL+HVL, addressing the limitation of the designers using HDLs (Verilog/ VHDL) and the verification engineers debating on HVLs (e/Vera). An extension of Verilog 2005 and largely based on OpenVera language, System Verilog became a darling of everyone from the Semiconductors as well as the EDA companies.

2. Standardization of HVLs e & SV - System Verilog was adopted as IEEE Standard 1800-2005 and then merged with the Verilog IEEE 1394-2005, leading to IEEE Standard 1800-2009. 'e' language promoted by Verisity and bought by Cadence went ahead getting standardized as IEEE 1647-2006. 

3. CDV - Code coverage stagnated as a baseline for measuring verification progress & completeness. Functional coverage supported by the HVLs was able to put forward a different dimension and widely accepted. Assertion coverage though promising wasn't able to spread its wings wide enough, partly, since it was scenario focussed and partly because of ownership issues between design & verification teams. Even test planning evolved a lot with many tools now aiding in developing a robust test plan by keeping a track of architecture document and extending means for defining comprehensive coverage goals upfront.

4. Reusability - A jargon that still makes news every now & then. Design complexity jumping new heights and time to market panic lead to evolution of IP designs and reusability. With design, verification IPs also defined their market quite strongly. Methodologies (eRM & RVM) helped in packaging the verification environment so as to make it portable from module to chip level and between programs. SV evolution brought in OVM & VMM complementing eRM & RVM respectively. [Note - OVM is a mix of eRM & AVM]. Finally, this decade will commence with standardization of methodology - UVM.

5. AMS - The intricacies of Analog always kept it behind the digital world in terms advancements in process technologies or other methodologies. Product demands from various domains lead to single chip (packaging) and later single die solutions. Since analog & digital designers were always alien to each other these integrated designs demanded verification. AMS simulations addressed this space with various schemes like - Gate level representation of digital & transistor level representation of analog, Gate level or RTL representation of digital & behavioral modeling of the analog etc.

6. Formal verification - Directed verification opened gates to constrained random verification (CRV) where unforseen scenario generation was the focus. Given time & compute resource limitations CRV struggled to reach all possible points in the designs in a defined time. Formal approach proposes to resolve these limitations. However, slow advancement on the simulators limited the adoption of this methodology for most part of the decade.

7. Low power verification - Area and performance had been defining ASIC designs until power became an important measure. Innovative design techniques reduced power consumption with an overhead logic. EDA tools capable of verifying power aware designs - MVSIM & MVRC from Archpro (later acquired by Synopsys) and Cadence IUS & Conformal LP did quite well to address this issue. UPF & CPF emerged as two power formats that rushed to address representation of power aware designs. [UPF - IEEE 1801-2009].
8. Hardware accelerators - More gates, big designs, long simulation run time = bottleneck to tapeout in time. Next generation of hardware accelarators paved way for reducing the simulation turn around time. These boxes soon took shape of a complete platform for verification of the whole system and further advanced to help simulate some real time data into the designs before tapeout with much ease.

9. HW SW co-verification - With design focus shifting from the ASIC to SOC, system design & modelling became all the more important. Software testing became the next chokepoint for time to market. A well defined platform where software design & testing could start in parallel to the ASIC design came forefront. Better HW SW partioning, performance checks, system design issues etc all were well addressed with this platform.

10. Courses in verification - VLSI course became more prominent and adopted in almost all electrical & electronics courses. Late in the decade a need for focussed verification courses took centre stage. Many institutes delivering these courses addressed the need for a competent verification work force.

Next -
'Predictions for future - the next decade!'

Previous -
'Recap from the past - the last decade!'

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